Constant ON time (COT) hysteresis converters are used in fast, dynamic response, voltage regulated (VR) systems. Fast, dynamic response VR systems include low voltage microprocessor and dual in-line memory module (DIMM) applications. COT hysteresis buck converters show attractive advantages such as a fast response time. Conventional multi-phase buck converters are built with voltage-mode or peak-current-mode buck structure that have a synchronized clock and several current sharing circuits. The conventional implementation is relatively slow compare to a COT hysteresis buck topology. When load conditions are increased, the multi-phase buck converter is needed to efficiently accommodate the heavy load transient. The nature of COT buck converters result in a switch frequency that does not have steady phase alignment. Using solutions based on digital signal processing (DSP) or peak current detection to implement a multiple phase hysteresis buck converter is impractical for mainstream applications. Without steady phase alignment, implementing multi-phase operation is a challenge.
It would be desirable to implement an auto-phase-shifting and dynamic ON time control current balancing multi-phase constant ON time buck converter.